Testing of interruptions. CH1 (yellow) is CANH, CH2 (blue) is CANL and CH3(pink) is interruption enable signal.

5us delay, 5us duration of interruption.

5us delay, 3us duration of interruption.

5us delay, 1us duration of interruption.

3us delay, 1us duration of interruption.

1us delay, 1us duration of interruption.


There is a visible two us inherent delay caused by firmware implementation (reaction time from transmission detection on CAN_TX pin to interrupt service routine handling and interruption generation). Theoretically it could be reduced down to below 1us with additional effort, because CAN_TX (from MCU to CAN transceiver) signal is actually the same as CANH or CANL signals (there is no phase shift). See below where CH1 (yellow) is CANH, CH2 (blue) is CANL and CH3(pink) is CAN_TX signal.